Add a docker build workflow #1

	name: Build and push docker image

	on:
	pull_request_target:
	branches: [ "main" ]
	types:
	- closed
	workflow_dispatch:

	jobs:
	build_docker:
	if: ${{ github.event_name == 'workflow_dispatch' \|\| github.event.pull_request.merged == true }}
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: Build app image
	run: docker build . --tag image

	- name: Log into registry
	run: echo "${{ secrets.REGISTRYPASSWORD }}" \| docker login registry.nordix.org -u ${{ secrets.REGISTRYUSERNAME }} --password-stdin

	- name: Push app image
	id: image
	run: \|
	IMAGE_ID=registry.nordix.org/eiffel/etos-environment-provider
	# Strip git ref prefix from version
	VERSION=$(echo "${{ github.ref }}" \| sed -e 's,./$.$,\1,')
	# Strip "v" prefix from tag name
	[[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION \| sed -e 's/^v//')
	# Use Docker `latest` tag convention
	[ "$VERSION" == "main" ] && VERSION=$(echo ${{ github.sha }} \| cut -c1-8)
	echo IMAGE_ID=$IMAGE_ID
	echo VERSION=$VERSION
	docker tag image $IMAGE_ID:$VERSION
	docker push $IMAGE_ID:$VERSION
	echo $IMAGE_ID:$VERSION

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